The invention relates to a loudspeaker system comprising an enclosure, a loudspeaker arrangement accommodated in the enclosure, a tube having one end connected to the enclosure, a volume bounded by the tube and communicating with a volume bounded by the enclosure, and a chamber connected to the tube and bounding a volume which communicates with the volume bounded by the tube.
A loudspeaker system of the type defined in the opening paragraph is known from EP 0,429,121 A1. The sound produced by the loudspeaker arrangement emanates from the open end of the long tube. An advantage of the use of a long tube is that the loudspeaker system becomes more sensitive, i.e. produces more acoustic output for the same electrical input, while the lowest resonant frequency hardly increases. With this known loudspeaker system it is possible to arrange the loudspeaker arrangement at a large distance from the exit aperture and to reduce the volume bounded by the housing while at the same time the tube length is increased, which yields greater freedom in the design of the loudspeaker system. This enables a stiff enclosure (cabinet) to be made with the result that cabinet resonances are minimal. The loudspeaker arrangement may comprise, for example, a cone loudspeaker or a plurality of cascaded loudspeakers. The chamber functions as a Helmholtz resonator and, when tuned correctly, suppresses the occurrence of standing waves (resonances) in the tube, which are a source of distortion of the output signal of the loudspeaker system. A correct tuning means inter alia that the volume of the chamber (Helmholtz resonator) should be related to the size of the loudspeaker arrangement. When a 51/4" loudspeaker is used the volume of the chamber should be approximately 1 liter whereas for an 8" loudspeaker the volume of the chamber should already be approximately 4 liters. The acoustic damper (Helmholtz resonator) is bulky, particularly in the last-mentioned case, and forms a comparatively expensive part.